抄録
Studies were made to clarify the nature of the coupling potentials which are produced, beside the EPSP's, in the eighth nerve fibers of goldfish in response to the sound stimulus. Analysis was made by studying semiquantitatively changes in the size of the coupling potentials, the EPSP's, and the microphonics upon changing the sound intensity; that is, an input-output relationship at the synapse between hair cells and eighth nerve fibers was studied. Results obtained are as follows:
1. The coupling potentials were produced without any delay after the initiation of the microphonic deflections and their time course was similar to that of the latter. Also the amplitude of these two potentials was changed in parallel upon changing the intensity of the sound stimulus.
2. EPSP's were produced with a definite delay after the initiation of the microphonics and their amplitude increased more steeply than the microphonics upon increasing the sound intensity. A 10dB increase in the sound intensity produced, in the exponential range, from 4- to 20-fold increase in the EPSP size.
3. The coupling potentials, like the microphonics, showed a greater resistance to cooling and anoxia.
4. It was concluded that the coupling potentials are quite different in nature from the EPSP's. While the EPSP's were generated in response to a released transmitter, the coupling potentials seem to have been produced in a more direct relationship with the microphonics.
